Securities Sold Under Agreements To Repurchase And Collateral Pledged By Counterparties (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Securities Sold Under Agreements To Repurchase [Abstract]
Gross amounts of recognized liabilities	$ 427,232		$ 443,370
Gross amounts offset in the statement of Condition	0		0
Net amounts of liabilities presented in the Statement of Condition	427,232	555,438	443,370
Offsetting securities purchased under agreements to resell	(30,584)		(2,068)
Securities Collateral	(396,639)		(441,273)
Net amount	$ 9		$ 29